1. Field of the Invention
The present invention relates to a method of reading data, method of transmitting data and mobile device thereof, and more particularly, to a method of reading data, method of transmitting data and mobile device thereof having a RAM-less display drive integrated circuit which uses a video mode to read image data.
2. Description of the Prior Art
A mobile industry processor interface (hereafter called MIPI) is commonly utilized in a mobile device for handling data transmission and reception between a processor and a display drive integrated circuit (IC) of the mobile device. The display drive IC may receive and read data transmitted from the processor, named host, according to the MIPI, such that the display drive IC drives a panel of the mobile device to display the data. The MIPI defines two application modes, one is a video mode and the other is a command mode. Basic hardware designs are made according to protocols based on the two modes, which significantly determine an optimization consideration between a production cost, a mechanical structure, a product size and a power consumption of the mobile device.
When using the video mode, a display drive IC without a random access memory (RAM), which refers to a RAM-less drive IC, may receive a vertical synchronization signal, a horizontal synchronization signal and image packets transmitted from the processor to refresh images on the panel synchronous with processor, such that the panel displays the images instantly. However, in such a structure, the processor has to continuously monitor a request from an operating system for updating images, transmit image packets to the display drive IC, and maintain an operation of the panel. Even in a static image, the processor has to transmit image packets to the display drive IC to maintain the operation of the panel, which not only wastes system resources of the mobile device but also increases the power consumption of the mobile device and leads to a risk of heat crash.
On the other, when using the command mode, the processor transmits the image packets to the display drive IC only when the image needs to be updated, and the processor does not transmit the vertical and horizontal synchronization signals to the display drive IC, which saves power consumption compared with the video mode. However, in such a structure, the display drive IC has to store image data in a built-in storage, such as a static random access memory (SRAM), and generate a vertical synchronization signal and a horizontal synchronization signal by itself to drive the panel displaying data of image packets, which increases a circuit area and a production cost of the display drive IC.
Therefore, how to pick up an advantage of having the RAM-less drive IC under the video mode and an advantage of power saving under the command mode in the MIPI, and exclude disadvantages of the video and command modes as much as possible, which has become a topic of the industry.